.container {
    width: 500px;
    height: 500px;
    border: 1px solid #000;
    overflow: auto;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);

    .list-phantom {
        position: absolute;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
    }

    .list-item {
        height: 50px;
        line-height: 50px;
        text-align: center;
        background-color: #f5f5f5;
        border-bottom: 1px solid #ccc;
    }
}